verilator/src/V3Order.cpp

// $Id$
//*************************************************************************
// DESCRIPTION: Verilator: Block code ordering
//
// Code available from: http://www.veripool.com/verilator
//
// AUTHORS: Wilson Snyder with Paul Wasson, Duane Gabli
//
//*************************************************************************
//
// Copyright 2003-2007 by Wilson Snyder.  This program is free software; you can
// redistribute it and/or modify it under the terms of either the GNU
// General Public License or the Perl Artistic License.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
//*************************************************************************
// V3Order's Transformations:
//		
//  Compute near optimal scheduling of always/wire statements
//  Make a graph of the entire netlist
//
//	Add master "*INPUTS*" vertex.
//	For inputs on top level
//	    Add vertex for each input var.
//		Add edge INPUTS->var_vertex
//
//	For seq logic
//	    Add logic_sensitive_vertex for this list of SenItems
//		Add edge for each sensitive_var->logic_sensitive_vertex	
//	    For AssignPre's	
//		Add vertex for this logic
//		    Add edge logic_sensitive_vertex->logic_vertex
//		    Add edge logic_consumed_var_PREVAR->logic_vertex
//		    Add edge logic_vertex->logic_generated_var (same as if comb)
//		    Add edge logic_vertex->generated_var_PREORDER
//			Cutable dependency to attempt to order dlyed
//			assignments to avoid saving state, thus we prefer
//				a <= b ...      As the opposite order would
//				b <= c ...	require the old value of b.
//	    For	Logic
//		Add vertex for this logic
//		    Add edge logic_sensitive_vertex->logic_vertex
//		    Add edge logic_generated_var_PREORDER->logic_vertex
//			This insures the AssignPre gets scheduled before this logic
//		    Add edge logic_vertex->consumed_var_PREVAR
//		    Add edge logic_vertex->consumed_var_POSTVAR
//		    Add edge logic_vertex->logic_generated_var (same as if comb)
//	    For AssignPost's
//		Add vertex for this logic
//		    Add edge logic_sensitive_vertex->logic_vertex
//		    Add edge logic_consumed_var->logic_vertex (same as if comb)
//		    Add edge logic_vertex->logic_generated_var (same as if comb)
//
//	For comb logic
//	    For comb logic
//		Add vertex for this logic
//		Add edge logic_consumed_var->logic_vertex
//		Add edge logic_vertex->logic_generated_var
//		    Mark it cutable, as circular logic may require
//		    the generated signal to become a primary input again.
//
//
#ifdef NEW_ORDERING
//   Determine nodes that form loops within combo logic
//      (Strongly connected ignoring assign post/pre's)
//   Make a subgraph for each loop of combo logic
//   Break circular logic in each subgraph
//
//   Determine nodes that form loops within a single eval call
//   Make a subgraph for each loop of sequential logic
//   Break circular logic in each subgraph
#endif
//
//   Rank the graph starting at INPUTS (see V3Graph)
//
//   Visit the graph's logic vertices in ranked order
//	For all logic vertices with all inputs already ordered
//	   Make ordered block for this module
//	   For all ^^ in same domain
//		Move logic to ordered activation
//	When we have no more choices, we move to the next module
//	and make a new block.  Add that new activation block to the list of calls to make.
//
//*************************************************************************

#include "config_build.h"
#include "verilatedos.h"
#include <stdio.h>
#include <stdarg.h>
#include <unistd.h>
#include <algorithm>
#include <vector>
#include <deque>
#include <map>
#include <iomanip>
#include <sstream>
#include <memory>

#include "V3Global.h"
#include "V3File.h"
#include "V3Ast.h"
#include "V3Graph.h"
#include "V3List.h"
#include "V3SenTree.h"
#include "V3Stats.h"
#include "V3EmitCBase.h"

#include "V3Order.h"
#include "V3OrderGraph.h"

class OrderMoveDomScope;

//######################################################################
// Functions for above graph classes

void OrderGraph::loopsVertexCb(V3GraphVertex* vertexp) {
    if (debug()) cout<<"-Info-Loop: "<<vertexp<<" "<<endl;
    if (OrderLogicVertex* vvertexp = dynamic_cast<OrderLogicVertex*>(vertexp)) {
	cout<<V3Error::msgPrefix()<<"     Example path: "<<vvertexp->nodep()->fileline()<<" "<<vvertexp->nodep()->typeName()<<endl;
    }
    if (OrderVarVertex* vvertexp = dynamic_cast<OrderVarVertex*>(vertexp)) {
	cout<<V3Error::msgPrefix()<<"     Example path: "<<vvertexp->varScp()->fileline()<<" "<<vvertexp->varScp()->prettyName()<<endl;
    }
};

//######################################################################

class OrderMoveDomScope {
    // Information stored for each unique loop, domain & scope trifecta
public:
    V3ListEnt<OrderMoveDomScope*>	m_readyDomScopeE;// List of next ready dom scope
    V3List<OrderMoveVertex*>	m_readyVertices;	// Ready vertices with same domain & scope
private:
    bool			m_onReadyList;		// True if DomScope is already on list of ready dom/scopes
    AstSenTree*			m_domainp;		// Domain all vertices belong to
    AstScope*			m_scopep;		// Scope all vertices belong to
    OrderLoopId			m_inLoop;		// Loop member of

    typedef pair<pair<OrderLoopId, AstSenTree*>, AstScope*> DomScopeKey;
    typedef std::map<DomScopeKey, OrderMoveDomScope*> DomScopeMap;
    static DomScopeMap	s_dsMap;	// Structure registered for each dom/scope pairing

public:
    OrderMoveDomScope(OrderLoopId inLoop, AstSenTree* domainp, AstScope* scopep)
	: m_onReadyList(false), m_domainp(domainp), m_inLoop(inLoop) {}
    OrderMoveDomScope* readyDomScopeNextp() const { return m_readyDomScopeE.nextp(); }
    OrderLoopId inLoop() const { return m_inLoop; }
    AstSenTree* domainp() const { return m_domainp; }
    AstScope*   scopep() const { return m_scopep; }
    void ready(OrderVisitor* ovp);	// Check the domScope is on ready list, add if not
    void movedVertex(OrderVisitor* ovp, OrderMoveVertex* vertexp);	// Mark one vertex as finished, remove from ready list if done
    // STATIC MEMBERS (for lookup)
    static void clear() {
	for (DomScopeMap::iterator it=s_dsMap.begin(); it!=s_dsMap.end(); ++it) {
	    delete it->second;
	}
	s_dsMap.clear();
    }
    V3List<OrderMoveVertex*>& readyVertices() { return m_readyVertices; }
    static OrderMoveDomScope* findCreate (OrderLoopId inLoop, AstSenTree* domainp, AstScope* scopep) {
	const DomScopeKey key = make_pair(make_pair(inLoop,domainp),scopep);
	DomScopeMap::iterator iter = s_dsMap.find(key);
	if (iter != s_dsMap.end()) {
	    return iter->second;
	} else {
	    OrderMoveDomScope* domScopep = new OrderMoveDomScope(inLoop, domainp, scopep);
	    s_dsMap.insert(make_pair(key, domScopep));
	    return domScopep;
	}
    }
    string name() const {
	return (string("MDS:")
		+" lp="+cvtToStr(inLoop())
		+" d="+cvtToStr((void*)domainp())
		+" s="+cvtToStr((void*)scopep()));
    }
};

OrderMoveDomScope::DomScopeMap	OrderMoveDomScope::s_dsMap;

inline ostream& operator<< (ostream& lhs, const OrderMoveDomScope& rhs) {
    lhs<<rhs.name();
    return lhs;
}

//######################################################################
// Order information stored under each AstNode::userp()...
 
// Types of vertex we can create
enum WhichVertex { WV_STD, WV_PRE, WV_PORD, WV_POST, WV_SETL,
		   WV_MAX};

class OrderUser {
    // Stored in AstVarScope::userp, a list of all the various vertices
    // that can exist for one given variable
private:
    OrderVarVertex*	m_vertexp[WV_MAX];	// Vertex of each type (if non NULL)
public:
    // METHODS
    OrderVarVertex* newVarUserVertex(V3Graph* graphp, AstScope* scopep,
				     AstVarScope* varscp, WhichVertex type, bool* createdp=NULL) {
	if (type>=WV_MAX) varscp->v3fatalSrc("Bad Case\n");
	OrderVarVertex* vertexp = m_vertexp[type];
	if (!vertexp) {
	    UINFO(6,"New vertex "<<varscp<<endl);
	    if (createdp) *createdp=true;
	    switch (type) {
	    case WV_STD:  vertexp = new OrderVarStdVertex   (graphp, scopep, varscp); break;
	    case WV_PRE:  vertexp = new OrderVarPreVertex   (graphp, scopep, varscp); break;
	    case WV_PORD: vertexp = new OrderVarPordVertex  (graphp, scopep, varscp); break;
	    case WV_POST: vertexp = new OrderVarPostVertex  (graphp, scopep, varscp); break;
	    case WV_SETL: vertexp = new OrderVarSettleVertex(graphp, scopep, varscp); break;
	    default: varscp->v3fatalSrc("Bad Case\n");
	    }
	    m_vertexp[type] = vertexp;
	} else {
	    if (createdp) *createdp=false;
	}
	return vertexp;
    }

public:    
    // CONSTRUCTORS
    OrderUser() {
	for (int i=0; i<WV_MAX; i++) m_vertexp[i]=NULL;
    }
    ~OrderUser() {}
};

//######################################################################
// Order class functions

class OrderVisitor : public AstNVisitor {
private:
    // NODE STATE
    // Forming graph:
    //   Entire Netlist:
    //    AstVarScope::userp	-> OrderUser* for usage var
    //	  AstActive::user3()	-> uint clocks hash of sensitivity list
    //    {statement}Node::userp-> AstModule* statement is under
    //   USER5 Cleared on each Logic stmt
    //    AstVarScope::user5()	-> VarUsage(gen/con/both).	Where already encountered signal
    // Ordering (user3/4/5 cleared between forming and ordering)
    //	  AstScope::userp()	-> AstModule*. Module this scope is under
    //    AstModule::user3()    -> Number of routines created

    //int debug() { return 9; }

    // STATE
    OrderGraph		m_graph;	// Scoreboard of var usages/dependencies
    SenTreeFinder	m_finder;	// Find global sentree's and add them
    AstSenTree*		m_comboDomainp;	// Combo activation tree
    AstSenTree*		m_deleteDomainp;// Delete this from tree
    AstSenTree*		m_settleDomainp;// Initial activation tree
    OrderInputsVertex*	m_inputsVxp;	// Top level vertex all inputs point from
    OrderSettleVertex*	m_settleVxp;	// Top level vertex all inputs point from
    OrderLogicVertex*	m_logicVxp;	// Current statement being tracked, NULL=ignored
    AstTopScope*	m_topScopep;	// Current top scope being processed
    AstScope*		m_scopetopp;	// Scope under TOPSCOPE
    AstModule*		m_modp;		// Current module
    AstScope*		m_scopep;	// Current scope being processed
    AstActive*		m_activep;	// Current activation block
    bool		m_inSenTree;	// Underneath AstSenItem; any varrefs are clocks
    bool		m_inClocked;	// Underneath clocked block
    bool		m_inPre;	// Underneath AstAssignPre
    bool		m_inPost;	// Underneath AstAssignPost
    OrderLogicVertex*	m_activeSenVxp;	// Sensitivity vertex
    deque<OrderUser*>	m_orderUserps;	// All created OrderUser's for later deletion.
    // STATE... for inside process
    OrderLoopId			m_loopIdMax;	// Maximum BeginLoop id number assigned
    vector<OrderLoopEndVertex*> m_pmlLoopEndps;	// processInsLoop: End vertex for each color
    vector<OrderLoopBeginVertex*> m_pomLoopMoveps;// processMoveLoop: Loops next nodes are under
    AstCFunc*			m_pomNewFuncp;	// Current function being created
    int				m_pomNewStmts;	// Statements in function being created
    V3Graph			m_pomGraph;	// Graph of logic elements to move
    V3List<OrderMoveVertex*>	m_pomWaiting;	// List of nodes needing inputs to become ready
protected:
    friend class OrderMoveDomScope;
    V3List<OrderMoveDomScope*>  m_pomReadyDomScope;	// List of ready domain/scope pairs, by loopId

private:
    // STATS
    V3Double0		m_statCut[OrderVEdgeType::_ENUM_END];	// Count of each edge type cut

    // TYPES
    enum VarUsage { VU_NONE=0, VU_CON=1, VU_GEN=2 };

    // METHODS
    void iterateNewStmt(AstNode* nodep) {
	if (m_scopep) {
	    UINFO(4,"   STMT "<<nodep<<endl);
	    //VV*****  We reset user5p()
	    AstNode::user5ClearTree();
	    if (!m_activep || !m_activep->sensesp()) nodep->v3fatalSrc("NULL");
	    // If inside combo logic, ignore the domain, we'll assign one based on interconnect
	    AstSenTree* startDomainp = m_activep->sensesp();
	    if (startDomainp->hasCombo()) startDomainp=NULL;
	    m_logicVxp = new OrderLogicVertex(&m_graph, m_scopep, startDomainp, nodep);
	    if (m_activeSenVxp) {
		// If in a clocked activation, add a link from the sensitivity to this block
		// Add edge logic_sensitive_vertex->logic_vertex
		new OrderEdge(&m_graph, m_activeSenVxp, m_logicVxp, WEIGHT_NORMAL);
	    }
	    nodep->userp(m_modp);
	    nodep->iterateChildren(*this);
	    m_logicVxp = NULL;
	}
    }

    OrderVarVertex* newVarUserVertex(AstVarScope* varscp, WhichVertex type, bool* createdp=NULL) {
	if (!varscp->userp()) {
	    OrderUser* newup = new OrderUser();
	    m_orderUserps.push_back(newup);
	    varscp->userp(newup);
	}
	OrderUser* up = (OrderUser*)(varscp->userp());
	return up->newVarUserVertex(&m_graph, m_scopep, varscp, type, createdp);
    }

    V3GraphEdge* findEndEdge(V3GraphVertex* vertexp, AstNode* errnodep, OrderLoopEndVertex*& evertexpr) {
	// Given a vertex, find the end block corresponding to it
	// Every vertex should have a pointer to the end block (one hopes)
	for (V3GraphEdge* edgep = vertexp->outBeginp(); edgep; edgep = edgep->outNextp()) {
	    if (OrderLoopEndVertex* evertexp = dynamic_cast<OrderLoopEndVertex*>(edgep->top())) {
		evertexpr = evertexp;
		return edgep;
	    }
	}
	errnodep->v3fatalSrc("Loop-broken vertex doesn't have pointer to LoopEndVertex: "<<vertexp);
	return NULL;
    }

    void process();
    void processLoops(string stepName, V3EdgeFuncP edgeFuncp);
    void processInsLoop();
    void processInsLoopEdge(V3GraphEdge* edgep);
    void processInsLoopNewEdge(V3GraphEdge* oldEdgep, V3GraphVertex* newFromp, V3GraphVertex* newTop);
    OrderVarVertex* processInsLoopNewVar(OrderVarVertex* oldVertexp, bool& createdr);
    void processBrokeLoop();
    void processCircular();
    void processSensitive();
    void processDomains();
    void processDomainsIterate(OrderEitherVertex* vertexp);
    void processEdgeReport();

    void processMove();
    void processMoveClear();
    void processMoveBuildGraph();
    void processMoveBuildGraphIterate (OrderMoveVertex* moveVxp, V3GraphVertex* vertexp, int weightmin);
    void processMovePrepScopes();
    void processMovePrepReady();
    void processMoveReadyOne(OrderMoveVertex* vertexp);
    void processMoveDoneOne(OrderMoveVertex* vertexp);
    void processMoveOne(OrderMoveVertex* vertexp, OrderMoveDomScope* domScopep, int level);
    void processMoveLoopPush(OrderLoopBeginVertex* beginp);
    void processMoveLoopPop(OrderLoopBeginVertex* beginp);
    void processMoveLoopStmt(AstNode* newSubnodep);
    OrderLoopId processMoveLoopCurrent();

    string cfuncName(AstModule* modp, AstSenTree* domainp, AstScope* scopep, AstNode* forWhatp) {
	modp->user3(1+modp->user3());
	int funcnum = modp->user3();
	string name = (domainp->hasCombo() ? "_combo"
		       : (domainp->hasInitial() ? "_initial"
			  : (domainp->hasSettle() ? "_settle"
			     : (domainp->isMulti() ? "_multiclk" : "_sequent"))));
	name = name+"__"+scopep->nameDotless()+"__"+cvtToStr(funcnum);
	if (v3Global.opt.profileCFuncs()) {
	    name += "__PROF__"+forWhatp->fileline()->profileFuncname();
	}
	return name;
    }

    void nodeMarkCircular(OrderVarVertex* vertexp, OrderEdge* edgep) {
	AstVarScope* nodep = vertexp->varScp();
	nodep->circular(true);
	m_statCut[vertexp->type()]++;
	if (edgep) m_statCut[edgep->type()]++;
	if (vertexp->isClock()) {
	    // Seems obvious; no warning yet
	    //nodep->v3warn(GENCLK,"Signal unoptimizable: Generated clock: "<<nodep->prettyName());
	} else if (nodep->varp()->isSigPublic()) {
	    nodep->v3warn(UNOPT,"Signal unoptimizable: Feedback to public clock or circular logic: "<<nodep->prettyName());
	    if (!nodep->fileline()->warnIsOff(V3ErrorCode::UNOPT)) {
		nodep->fileline()->warnOff(V3ErrorCode::UNOPT, true);  // Complain just once
		// Give the user an example.
		bool tempWeight = (edgep && edgep->weight()==0);
		if (tempWeight) edgep->weight(1);  // Else the below loop detect can't see the loop
		m_graph.reportLoops(&OrderEdge::followComboConnected, vertexp); // calls OrderGraph::loopsVertexCb
		if (tempWeight) edgep->weight(0);
	    }
	} else {
	    // We don't use UNOPT, as there are lots of V2 places where it was needed, that aren't any more
	    // First v3warn not inside warnIsOff so we can see the suppressions with --debug
	    nodep->v3warn(UNOPTFLAT,"Signal unoptimizable: Feedback to clock or circular logic: "<<nodep->prettyName());
	    if (!nodep->fileline()->warnIsOff(V3ErrorCode::UNOPTFLAT)) {
		nodep->fileline()->warnOff(V3ErrorCode::UNOPTFLAT, true);  // Complain just once
		// Give the user an example.
		bool tempWeight = (edgep && edgep->weight()==0);
		if (tempWeight) edgep->weight(1);  // Else the below loop detect can't see the loop
		m_graph.reportLoops(&OrderEdge::followComboConnected, vertexp); // calls OrderGraph::loopsVertexCb
		if (tempWeight) edgep->weight(0);
	    }
	}
    }

    // VISITORS
    virtual void visit(AstNetlist* nodep, AstNUser*) {
	nodep->iterateChildren(*this);
	// We're finished, complete any unfinished topscopes
	if (m_topScopep) { process(); m_topScopep=NULL; }
    }
    virtual void visit(AstTopScope* nodep, AstNUser*) {
	// Process the last thing we're finishing
	if (m_topScopep) { process(); m_topScopep=NULL; }
	UINFO(2,"  Loading tree...\n");
	//VV*****  We reset userp()
	AstNode::userClearTree();
	AstNode::user3ClearTree();
	m_graph.clear();
	m_activep = NULL;
	m_topScopep = nodep;
	m_scopetopp = nodep->scopep();
	// Find sentree's
	m_finder.main(m_topScopep);
	// ProcessDomainsIterate will use these when it needs to move
	// something to a combodomain.  This saves a ton of find() operations.
	AstSenTree* combp = new AstSenTree (nodep->fileline(),	// Gets cloned() so ok if goes out of scope
					    new AstSenItem(nodep->fileline(), AstSenItem::Combo()));
	m_comboDomainp = m_finder.getSenTree(nodep->fileline(), combp);
	pushDeletep(combp);  // Cleanup when done
	AstSenTree* settlep = new AstSenTree (nodep->fileline(),  // Gets cloned() so ok if goes out of scope
					      new AstSenItem(nodep->fileline(), AstSenItem::Settle()));
	m_settleDomainp = m_finder.getSenTree(nodep->fileline(), settlep);
	pushDeletep(settlep);  // Cleanup when done
	// Fake AstSenTree we set domainp to indicate needs deletion
	m_deleteDomainp = new AstSenTree (nodep->fileline(),
					  new AstSenItem(nodep->fileline(), AstSenItem::Settle()));
	pushDeletep(m_deleteDomainp);  // Cleanup when done
	UINFO(5,"    DeleteDomain = "<<m_deleteDomainp<<endl);
	// Base vertices
	m_activeSenVxp = NULL;
#ifdef NEW_ORDERING
	m_inputsVxp = new OrderInputsVertex(&m_graph, m_comboDomainp);
	m_settleVxp = new OrderSettleVertex(&m_graph, m_settleDomainp);
#else
	m_inputsVxp = new OrderInputsVertex(&m_graph, NULL);
#endif
	//
	nodep->iterateChildren(*this);
	// Done topscope, erase extra user information
	// userp passed to next process() operation
	AstNode::user3ClearTree();
	AstNode::user5ClearTree();
    }
    virtual void visit(AstModule* nodep, AstNUser*) {
	m_modp = nodep;
	nodep->iterateChildren(*this);
    }
    virtual void visit(AstScope* nodep, AstNUser*) {
	UINFO(4," SCOPE "<<nodep<<endl);
	m_scopep = nodep;
	m_logicVxp = NULL;
	m_activeSenVxp = NULL;
	nodep->userp(m_modp);
	// Iterate
	nodep->iterateChildren(*this);
	m_scopep = NULL;
    }
    virtual void visit(AstActive* nodep, AstNUser*) {
	// Create required activation blocks and add to module
	if (nodep->hasInitial()) return;  // Ignore initials
	UINFO(4,"  ACTIVE  "<<nodep<<endl);
	m_activep = nodep;
	m_activeSenVxp = NULL;
	m_inClocked = nodep->hasClocked();
	// Compute hash of sensitivity list
	V3Hash clocks;
	if (nodep->sensesp()) {
	    for (AstSenItem* senp = nodep->sensesp()->sensesp(); senp; senp=senp->nextp()->castSenItem()) {
		clocks = V3Hash(clocks, V3Hash(senp->edgeType()));
		if (senp->varrefp()) {
		    clocks = V3Hash(clocks, V3Hash(senp->varrefp()->varScopep()));
		}
	    }
	}
	nodep->user3(clocks.hshval());
	// Grab the sensitivity list
	if (nodep->sensesStorep()) nodep->v3fatalSrc("Senses should have been activeTop'ed to be global!");
	nodep->sensesp()->accept(*this);
	// Collect statements under it
	nodep->iterateChildren(*this);
	m_activep = NULL;
    }
    virtual void visit(AstVarScope* nodep, AstNUser*) {
	// Create links to all input signals
	if (m_modp->isTop() && nodep->varp()->isInput()) {
	    OrderVarVertex* varVxp = newVarUserVertex(nodep, WV_STD);
	    new OrderEdge(&m_graph, m_inputsVxp, varVxp, WEIGHT_INPUT);
	}
    }
    virtual void visit(AstNodeVarRef* nodep, AstNUser*) {
	if (m_scopep) {
	    AstVarScope* varscp = nodep->varScopep();
	    if (!varscp) nodep->v3fatalSrc("Var didn't get varscoped in V3Scope.cpp\n");
	    if (m_inSenTree) {
		// Add CLOCK dependency... This is a root of the tree we'll trace
		if (nodep->lvalue()) nodep->v3fatalSrc("How can a sensitivity be setting a var?\n");
		OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_STD);
		varVxp->isClock(true);
		new OrderEdge(&m_graph, varVxp, m_activeSenVxp, WEIGHT_MEDIUM);
	    } else {
		if (!m_logicVxp) nodep->v3fatalSrc("Var ref not under a logic block\n");
		// What new directions is this used
		// We don't want to add extra edges if the logic block has many usages of same var
		bool gen = false;
		bool con = false;
		if (nodep->lvalue()) {
		    gen = !(varscp->user5() & VU_GEN);
		} else {
		    con = !(varscp->user5() & VU_CON);
		    if ((varscp->user5() & VU_GEN) && !m_inClocked) {
			// Dangerous assumption:
			// If a variable is used in the same activation which defines it first,
			// consider it something like:
			//		foo = 1
			//		foo = foo + 1
			// and still optimize.  This is the rule verilog-mode assumes for /*AS*/
			// Note this will break though:
			//		if (sometimes) foo = 1
			//		foo = foo + 1
			con = false;
		    }
		    if (varscp->varp()->attrClockEn() && !m_inPre && !m_inPost && !m_inClocked) {
			// clock_enable attribute: user's worring about it for us
			con = false;
		    }
		}
		if (gen) varscp->user5(varscp->user5() | VU_GEN);
		if (con) varscp->user5(varscp->user5() | VU_CON);
		// Add edges
		if (!m_inClocked
		    || m_inPost
		    ) {
		    // Combo logic
		    if (
#ifdef NEW_ORDERING
			m_activep && m_activep->hasSettle()
#else
			0
#endif
			) {
			// Inside settlement; we use special variable names to prevent
			// having extra logic to break arcs within
			if (gen) {
			    // Add edge logic_vertex->logic_generated_var
			    bool created = false;
			    OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_SETL, &created);
			    new OrderComboCutEdge(&m_graph, m_logicVxp, varVxp);
#ifdef NEW_ORDERING
			    if (created) new OrderEdge(&m_graph, m_settleVxp, varVxp, WEIGHT_INPUT);
#endif
			}
			if (con) {
			    // Add edge logic_consumed_var->logic_vertex
			    bool created = false;
			    OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_SETL, &created);
			    new OrderEdge(&m_graph, varVxp, m_logicVxp, WEIGHT_MEDIUM);
#ifdef NEW_ORDERING
			    if (created) new OrderEdge(&m_graph, m_settleVxp, varVxp, WEIGHT_INPUT);
#endif
			}
		    } else { // not settle and (combo or inPost)
			if (gen) {
			    // Add edge logic_vertex->logic_generated_var
			    OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_STD);
			    if (m_inPost) {
				new OrderPostCutEdge(&m_graph, m_logicVxp, varVxp);
			    } else {
				new OrderComboCutEdge(&m_graph, m_logicVxp, varVxp);
			    }
			    // For m_inPost:
			    //    Add edge consumed_var_POST->logic_vertex
			    //    This prevents a consumer of the "early" value to be scheduled
			    //   after we've changed to the next-cycle value
			    // ALWAYS do it:
			    //    There maybe a wire a=b; between the two blocks
			    OrderVarVertex* postVxp = newVarUserVertex(varscp, WV_POST);
			    new OrderEdge(&m_graph, postVxp, m_logicVxp, WEIGHT_POST);
			}
			if (con) {
			    // Add edge logic_consumed_var->logic_vertex
			    OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_STD);
			    new OrderEdge(&m_graph, varVxp, m_logicVxp, WEIGHT_MEDIUM);
			}
		    }
		} else if (m_inPre) {
		    // AstAssignPre logic
		    if (gen) {
			// Add edge logic_vertex->generated_var_PREORDER
			OrderVarVertex* ordVxp = newVarUserVertex(varscp, WV_PORD);
			new OrderEdge(&m_graph, m_logicVxp, ordVxp, WEIGHT_NORMAL);
			// Add edge logic_vertex->logic_generated_var (same as if comb)
			OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_STD);
			new OrderEdge(&m_graph, m_logicVxp, varVxp, WEIGHT_NORMAL);
		    }
		    if (con) {
			// Add edge logic_consumed_var_PREVAR->logic_vertex
			// This one is cutable (vs the producer) as there's only one of these, but many producers
			OrderVarVertex* preVxp = newVarUserVertex(varscp, WV_PRE);
			new OrderPreCutEdge(&m_graph, preVxp, m_logicVxp);
		    }
		} else {
		    // Seq logic
		    if (gen) {
			// Add edge logic_generated_var_PREORDER->logic_vertex
			OrderVarVertex* ordVxp = newVarUserVertex(varscp, WV_PORD);
			new OrderEdge(&m_graph, ordVxp, m_logicVxp, WEIGHT_NORMAL);
			// Add edge logic_vertex->logic_generated_var (same as if comb)
			OrderVarVertex* varVxp = newVarUserVertex(varscp, WV_STD);
			new OrderEdge(&m_graph, m_logicVxp, varVxp, WEIGHT_NORMAL);
		    }
		    if (con) {
			// Add edge logic_vertex->consumed_var_PREVAR
			// Generation of 'pre' because we want to indicate it should be before AstAssignPre
			OrderVarVertex* preVxp = newVarUserVertex(varscp, WV_PRE);
			new OrderEdge(&m_graph, m_logicVxp, preVxp, WEIGHT_NORMAL);
			// Add edge logic_vertex->consumed_var_POST
			OrderVarVertex* postVxp = newVarUserVertex(varscp, WV_POST);
			new OrderEdge(&m_graph, m_logicVxp, postVxp, WEIGHT_POST);
		    }
		}
	    }
	}
    }
    virtual void visit(AstSenTree* nodep, AstNUser*) {
	// Having a node derived from the sentree isn't required for
	// correctness, it mearly makes the graph better connected
	// and improves graph algorithmic performance
	if (m_scopep) {	// Else TOPSCOPE's SENTREE list
	    m_inSenTree = true;
	    if (nodep->hasClocked()) {
		if (!m_activeSenVxp) {
		    m_activeSenVxp = new OrderLogicVertex(&m_graph, m_scopep, nodep, m_activep);
		}
		nodep->iterateChildren(*this);
	    }
	    m_inSenTree = false;
	}
    }
    virtual void visit(AstAlways* nodep, AstNUser*) {
	iterateNewStmt(nodep);
    }
    virtual void visit(AstAlwaysPost* nodep, AstNUser*) {
	m_inPost = true;
	iterateNewStmt(nodep);
	m_inPost = false;
    }
    virtual void visit(AstAssignAlias* nodep, AstNUser*) {
	iterateNewStmt(nodep);
    }
    virtual void visit(AstAssignW* nodep, AstNUser*) {
	iterateNewStmt(nodep);
    }
    virtual void visit(AstAssignPre* nodep, AstNUser*) {
	m_inPre = true;
	iterateNewStmt(nodep);
	m_inPre = false;
    }
    virtual void visit(AstAssignPost* nodep, AstNUser*) {
	m_inPost = true;
	iterateNewStmt(nodep);
	m_inPost = false;
    }
    virtual void visit(AstCFunc*, AstNUser*) {
	// Ignore for now
	// We should detect what variables are set in the function, and make
	// settlement code for them, then set a global flag, so we call "settle"
	// on the next evaluation loop.
    }
    //--------------------
    // Default
    virtual void visit(AstNode* nodep, AstNUser*) {
	nodep->iterateChildren(*this);
    }
public:
    // CONSTUCTORS
    OrderVisitor() {
	m_topScopep = NULL;
	m_scopetopp = NULL;
	m_modp = NULL;
	m_scopep = NULL;
	m_activep = NULL;
	m_inSenTree = false;
	m_inClocked = false;
	m_inPre = m_inPost = false;
	m_comboDomainp = NULL;
	m_deleteDomainp = NULL;
	m_settleDomainp = NULL;
	m_settleVxp = NULL;
	m_inputsVxp = NULL;
	m_loopIdMax = LOOPID_FIRST;
	m_pomNewStmts = 0;
	if (debug()) m_graph.debug(5); // 3 is default if global debug; we want acyc debugging
    }
    virtual ~OrderVisitor() {
	// Stats
	for (int type=0; type<OrderVEdgeType::_ENUM_END; type++) {
	    if (double count = double(m_statCut[type])) {
		V3Stats::addStat(string("Order, cut, ")+OrderVEdgeType(type).ascii(), count);
	    }
	}
	// Destruction
	for (deque<OrderUser*>::iterator it=m_orderUserps.begin(); it!=m_orderUserps.end(); ++it) {
	    delete *it;
	}
	m_graph.debug(V3Error::debugDefault());
    }
    void main(AstNode* nodep) {
	nodep->accept(*this);
    }
};

//######################################################################
// Pre-Loop elimination

void OrderVisitor::processInsLoop() {
    // Input is graph with color() reflecting the sub-graphs we need
    // to loop remove.  Take all the I/O from each subgraph and route
    // through a new begin/end vertex
    // Note we DON'T only do certain edges; we want all edges to be preserved,
    // we'll select which are important later on.

    uint32_t maxcolor = 0;
    for (V3GraphVertex* vertexp = m_graph.verticesBeginp(); vertexp; vertexp=vertexp->verticesNextp()) {
	if (maxcolor <= vertexp->color()) maxcolor = vertexp->color() + 1;
	if (OrderVarVertex* vvertexp = dynamic_cast<OrderVarVertex*>(vertexp)) {
	    vvertexp->pilNewVertexp(NULL);  // Clear user-ish information before loop
	}
    }

    m_pmlLoopEndps.clear();
    m_pmlLoopEndps.reserve(maxcolor);
    m_pmlLoopEndps.assign(maxcolor,NULL);

    m_graph.userClearVertices();  // Vertex::user()   // true if added as begin/end
    for (V3GraphVertex* vertexp = m_graph.verticesBeginp(); vertexp; vertexp=vertexp->verticesNextp()) {
	if (uint32_t loopColor = vertexp->color()) {
	    OrderEitherVertex* evertexp = dynamic_cast<OrderEitherVertex*>(vertexp);
	    if (!evertexp) v3fatalSrc("Non either vertex found");
	    if (!vertexp->user()) {
		UINFO(8,"      pil:nowInLoop lp="<<m_loopIdMax<<" waslp="
		      <<evertexp->inLoop()<<" "<<evertexp<<endl);
		if (!m_pmlLoopEndps[loopColor]) {
		    AstUntilStable* untilp = new AstUntilStable(m_topScopep->fileline(), NULL, NULL);
		    m_topScopep->addStmtsp(untilp);
		    OrderLoopBeginVertex* beginp
			= new OrderLoopBeginVertex(&m_graph, m_scopetopp,
						   evertexp->domainp(),
						   untilp,
						   m_loopIdMax, loopColor);
		    m_loopIdMax = (OrderLoopId)(m_loopIdMax+1);
		    UASSERT(LOOPID_MAX>m_loopIdMax, "loopid overflow "<<m_loopIdMax<<" "<<LOOPID_MAX);
		    OrderLoopEndVertex* endp = new OrderLoopEndVertex(&m_graph, beginp);
		    new OrderEdge(&m_graph, beginp, endp, WEIGHT_LOOPBE);
		    m_pmlLoopEndps[loopColor] = endp;
		    // Color edges to belong to subgraph
		    beginp->color(loopColor);
		    endp->color(loopColor);
		    beginp->user(1);  // Added; don't iterate on it
		    endp->user(1);  // Added; don't iterate on it
		}
		if (evertexp->inLoop()) {
		    // Adding node to loop, but already in loop...
		    // Ok if the nodes were a combo loop and now become a sequent loop,
		    // The combo loop will be "under" the sequent loop, so keep the combo #.
		    //UINFO(9, "Adding node to loop, but already in loop: "<<evertexp->name()<<endl);
		} else {
		    // Make all nodes point from/to the begin/end nodes
		    OrderLoopEndVertex* endp = m_pmlLoopEndps[loopColor];
		    OrderLoopBeginVertex* beginp = endp->beginVertexp();
		    new OrderEdge(&m_graph, beginp, vertexp, WEIGHT_LOOPBE);
		    new OrderEdge(&m_graph, vertexp, endp, WEIGHT_LOOPBE);
		    evertexp->inLoop(beginp->loopId());
		}
	    }
	}
    }

    m_graph.userClearEdges();	// Edge::user()		// true if we added it
    for (V3GraphVertex* vertexp = m_graph.verticesBeginp(); vertexp; vertexp=vertexp->verticesNextp()) {
	if (vertexp->color()) {
	    for (V3GraphEdge* nextp,* edgep = vertexp->outBeginp(); edgep; edgep = nextp) {
		nextp = edgep->outNextp();  // Func may edit the list
		if (edgep->weight()) {
		    processInsLoopEdge(edgep);
		} else {  // No purpose to this edge any longer
		    edgep->unlinkDelete(); edgep=NULL;	// remove old edge
		}
	    }
	    for (V3GraphEdge* nextp,* edgep = vertexp->inBeginp(); edgep; edgep = nextp) {
		nextp = edgep->inNextp();  // Func may edit the list
		if (edgep->weight()) { 
		    processInsLoopEdge(edgep);
		} else {  // No purpose to this edge any longer
		    edgep->unlinkDelete(); edgep=NULL;	// remove old edge
		}
	    }
	}
    }

    // Done with space
    m_pmlLoopEndps.clear();
}

void OrderVisitor::processInsLoopNewEdge(V3GraphEdge* oldEdgep, V3GraphVertex* newFromp, V3GraphVertex* newTop) {
    // Create new edge based on the old edge's parameters
    const OrderEdge* oedgep = dynamic_cast<const OrderEdge*>(oldEdgep);
    V3GraphEdge* newEdgep = oedgep->clone(&m_graph, newFromp, newTop);
    newEdgep->user(1);	// New edge doesn't need to be changed
}

OrderVarVertex* OrderVisitor::processInsLoopNewVar(OrderVarVertex* oldVertexp, bool& createdr) {
    // Create new VarVertex from given template
    if (oldVertexp->pilNewVertexp()) {
	createdr = false;
    } else {
	OrderVarVertex* newVertexp = oldVertexp->clone(&m_graph);
	oldVertexp->pilNewVertexp(newVertexp);
	createdr = true;
    }
    return oldVertexp->pilNewVertexp();
}

void OrderVisitor::processInsLoopEdge(V3GraphEdge* oldEdgep) {
    if (!oldEdgep->user()) { // if not processed
	oldEdgep->user(1);  // mark as processed
	if (oldEdgep->fromp()->color() == oldEdgep->top()->color()) {
	    return; // Doesn't cross subgraphs
	} else {
	    V3GraphVertex* newFromp = oldEdgep->fromp();
	    V3GraphVertex* newTop   = oldEdgep->top();
	    //UINFO(6, "      pile: "<<newFromp<<" -> "<<newTop<<endl);
	    if (uint32_t fromId = oldEdgep->fromp()->color()) {
		// Change to come from end block
		OrderLoopEndVertex* endp = m_pmlLoopEndps[fromId];
		newFromp = endp;
		// If it goes from(to) a cutable VarVertex inside the Begin/End block,
		// we can't loose the variable, as we might need to cut that variable out
		// in the next pass of processLoops, and processBrokeLoops needs the var pointer.
		// We'll make another VarVertex (dup of the one "inside" the loop)
		// and point to it.
		if (oldEdgep->cutable()) {
		    if (OrderVarVertex* vvFromp = dynamic_cast<OrderVarVertex*>(oldEdgep->fromp())) {
			// end => newvarvtx -> {whatever}
			bool created;
			newFromp = processInsLoopNewVar(vvFromp, created/*ref*/);
			if (created) processInsLoopNewEdge(oldEdgep, endp, newFromp);
		    }
		}
	    }
	    if (uint32_t toId = oldEdgep->top()->color()) {
		// Change to go to begin block
		OrderLoopEndVertex* endp = m_pmlLoopEndps[toId];
		OrderLoopBeginVertex* beginp = endp->beginVertexp();
		newTop = beginp;
		// Ditto above
		if (oldEdgep->cutable()) {
		    if (OrderVarVertex* vvTop = dynamic_cast<OrderVarVertex*>(oldEdgep->top())) {
			// oldfrom -> newvarvtx => begin
			bool created;
			newTop = processInsLoopNewVar(vvTop, created/*ref*/);
			if (created) processInsLoopNewEdge(oldEdgep, newTop, beginp);
		    }
		}
	    }

	    // New edge with appropriate to/from
	    processInsLoopNewEdge(oldEdgep, newFromp, newTop);
	    oldEdgep->unlinkDelete(); oldEdgep=NULL;	// remove old edge
	}
    }
}

//######################################################################
// Pre-Loop elimination

// NEW_ORDERING
void OrderVisitor::processBrokeLoop() {
    // Find those loops that were broken
    for (V3GraphVertex* vertexp = m_graph.verticesBeginp(); vertexp; vertexp=vertexp->verticesNextp()) {
	// Above processInsLoopEdge makes sure there's always a OrderVarVertex on
	// boundaries to/from LoopBegin/EndVertex'es
	if (OrderVarVertex* vvertexp = dynamic_cast<OrderVarVertex*>(vertexp)) {
	    // Any cut edges?
	    bool anyCut = false;
	    for (V3GraphEdge* nextp,* edgep = vertexp->inBeginp(); edgep; edgep = nextp) {
		nextp = edgep->inNextp();  // We may edit the list
		if (edgep->weight()==0) { // was cut
		    anyCut = true;
		    edgep->unlinkDelete(); edgep=NULL;	// remove old edge
		}
	    }
	    for (V3GraphEdge* nextp,* edgep = vertexp->outBeginp(); edgep; edgep = nextp) {
		nextp = edgep->outNextp();  // We may edit the list
		if (edgep->weight()==0) { // was cut
		    anyCut = true;
		    edgep->unlinkDelete(); edgep=NULL;	// remove old edge
		}
	    }
	    if (anyCut) {
		UINFO(6,"      pbl: Cut "<<vertexp->name()<<endl);
		nodeMarkCircular(vvertexp, NULL);
		OrderLoopEndVertex* endp = NULL; // Set below in findEndEdge
		V3GraphEdge* endedgep = findEndEdge(vertexp, vvertexp->varScp(), endp/*ref*/);
		// Add edge to graphically indicate change detect required
		endedgep->unlinkDelete(); endedgep=NULL;	// remove old edge
		new OrderChangeDetEdge(&m_graph, vvertexp, endp);
		// Add variable dependency to until loop
		AstUntilStable* untilp = endp->beginVertexp()->untilp();
		untilp->addStablesp(new AstVarRef(vvertexp->varScp()->fileline(), vvertexp->varScp(), false));
	    }
	}
    }
}

//######################################################################
// Circular detection

#ifndef NEW_ORDERING
void OrderVisitor::processCircular() {
    // Take broken edges and add circular flags
    // The change detect code will use this to force changedets
    for (V3GraphVertex* itp = m_graph.verticesBeginp(); itp; itp=itp->verticesNextp()) {
	if (OrderVarStdVertex* vvertexp = dynamic_cast<OrderVarStdVertex*>(itp)) {
	    if (vvertexp->isClock() && !vvertexp->varScp()->varp()->isPrimaryIn()) {
		// If a clock is generated internally, we need to do another loop
		// through the entire evaluation.  This fixes races; see t_clk_dpulse test.
		UINFO(5,"Circular Clock "<<vvertexp<<endl);
		nodeMarkCircular(vvertexp, NULL);
	    }
	    // Also mark any cut edges
	    for (V3GraphEdge* edgep = vvertexp->outBeginp(); edgep; edgep=edgep->outNextp()) {
		if (edgep->weight()==0) { // was cut
		    OrderEdge* oedgep = dynamic_cast<OrderEdge*>(edgep);
		    if (!oedgep) vvertexp->varScp()->v3fatalSrc("Cuttable edge not of proper type");
		    nodeMarkCircular(vvertexp, oedgep);
		}
	    }
	    for (V3GraphEdge* edgep = vvertexp->inBeginp(); edgep; edgep = edgep->inNextp()) {
		if (edgep->weight()==0) { // was cut
		    OrderEdge* oedgep = dynamic_cast<OrderEdge*>(edgep);
		    if (!oedgep) vvertexp->varScp()->v3fatalSrc("Cuttable edge not of proper type");
		    nodeMarkCircular(vvertexp, oedgep);
		}
	    }
	}
    }
}
#endif

void OrderVisitor::processSensitive() {
    // Sc sensitives are required on all inputs that go to a combo
    // block.  (Not inputs that go only to clocked blocks.)
    for (V3GraphVertex* itp = m_graph.verticesBeginp(); itp; itp=itp->verticesNextp()) {
	if (OrderVarStdVertex* vvertexp = dynamic_cast<OrderVarStdVertex*>(itp)) {
	    if (vvertexp->varScp()->varp()->isInput()) {
		//UINFO(0,"  scsen "<<vvertexp<<endl);
		for (V3GraphEdge* edgep = vvertexp->outBeginp(); edgep; edgep=edgep->outNextp()) {
		    if (OrderEitherVertex* toVertexp = dynamic_cast<OrderEitherVertex*>(edgep->top())) {
			if (edgep->weight() && toVertexp->domainp()) {
			    //UINFO(0,"      "<<toVertexp->domainp()<<endl);
			    if (toVertexp->domainp()->hasCombo()) {
				vvertexp->varScp()->varp()->scSensitive(true);
			    }
			}
		    }
		}
	    }
	}
    }
}

void OrderVisitor::processDomains() {
    for (V3GraphVertex* itp = m_graph.verticesBeginp(); itp; itp=itp->verticesNextp()) {
	OrderEitherVertex* vertexp = dynamic_cast<OrderEitherVertex*>(itp);
	UASSERT(vertexp, "Null or vertex not derived from EitherVertex\n");
	processDomainsIterate(vertexp);
    }
}

void OrderVisitor::processDomainsIterate(OrderEitherVertex* vertexp) {
    // The graph routines have already sorted the vertexes and edges into best->worst order
    // Assign clock domains to each signal.
    //     Sequential logic is forced into the same sequential domain.
    //     Combo logic may be pushed into a seq domain if all its inputs are the same domain,
    //     else, if all inputs are from flops, it's end-of-sequential code
    //     else, it's full combo code
    if (!vertexp->inLoop()) vertexp->inLoop(LOOPID_NOTLOOPED);
    if (vertexp->domainp()) return;	// Already processed, or sequential logic
    UINFO(5,"    pdi: "<<vertexp<<endl);
    OrderVarVertex* vvertexp = dynamic_cast<OrderVarVertex*>(vertexp);
    AstSenTree* domainp = NULL;
    UASSERT(m_comboDomainp, "not preset");
#ifndef NEW_ORDERING  // New ordering set the input node as combo, so this happens automatically
    if (vvertexp && vvertexp->varScp()->varp()->isInput()) {
	domainp = m_comboDomainp;
    }
#endif
    if (vvertexp && vvertexp->varScp()->isCircular()) {
	domainp = m_comboDomainp;
    }
    if (!domainp) {
	for (V3GraphEdge* edgep = vertexp->inBeginp(); edgep; edgep = edgep->inNextp()) {
	    OrderEitherVertex* fromVertexp = (OrderEitherVertex*)edgep->fromp();
	    if (edgep->weight()
#ifndef NEW_ORDERING
		&& fromVertexp->domainMatters()
#endif
		) {
		UINFO(9,"     from d="<<(void*)fromVertexp->domainp()<<" "<<fromVertexp<<endl);
		if (!domainp  // First input to this vertex
		    || domainp->hasSettle()) {	// or, we can ignore being in the settle domain
		    domainp = fromVertexp->domainp();
		}
		else if (domainp->hasCombo()) {
		    // Once in combo, keep in combo; already as severe as we can get
		}
		else if (fromVertexp->domainp()->hasCombo()) {
		    // Any combo input means this vertex must remain combo
		    domainp = m_comboDomainp;
		}
		else if (fromVertexp->domainp()->hasSettle()) {
		    // Ignore that we have a constant (initial) input
		}
		else if (domainp != fromVertexp->domainp()) {
		    // Make a domain that merges the two domains
		    bool ddebug = debug()>=9;
		    if (ddebug) {
			cout<<endl;
			UINFO(0,"      conflicting domain "<<fromVertexp<<endl);
			UINFO(0,"         dorig="<<domainp<<endl);
			domainp->dumpTree(cout);
			UINFO(0,"         d2   ="<<fromVertexp->domainp()<<endl);
			fromVertexp->domainp()->dumpTree(cout);
		    }
		    AstSenTree* newtreep = domainp->cloneTree(false)->castSenTree();
		    AstSenItem* newtree2p = fromVertexp->domainp()->sensesp()->cloneTree(true)->castSenItem();
		    if (!newtree2p) fromVertexp->domainp()->v3fatalSrc("No senitem found under clocked domain");
		    newtreep->addSensesp(newtree2p);
		    newtreep->sortSenses();	// Remove duplicates
		    newtreep->multi(true);	// Comment that it was made from 2 clock domains
		    domainp = m_finder.getSenTree(domainp->fileline(), newtreep);
		    if (ddebug) {
			UINFO(0,"         dnew ="<<newtreep<<endl);
			newtreep->dumpTree(cout);
			UINFO(0,"         find ="<<domainp<<endl);
			domainp->dumpTree(cout);
			cout<<endl;
		    }
		    newtreep->deleteTree(); newtreep=NULL;
		}
	    }
	} // next input edgep
	// Default the domain
	// This is a node which has only constant inputs, or is otherwise indeterminate.
	// It should have already been copied into the settle domain.  Presumably it has
	// inputs which we never trigger, or nothing it's sensitive to, so we can rip it out.
	if (!domainp && vertexp->scopep()) {
	    domainp = m_deleteDomainp;
	}
    }
    //
    vertexp->domainp(domainp);
    if (vertexp->domainp()) {
	UINFO(5,"      done d="<<(void*)vertexp->domainp()
	      <<(vertexp->domainp()->hasCombo()?" [COMB]":"")
	      <<(vertexp->domainp()->isMulti()?" [MULT]":"")
	      <<" "<<vertexp<<endl);
    }
}

//######################################################################
// Move graph construction

void OrderVisitor::processEdgeReport() {
    // Make report of all signal names and what clock edges they have
    string filename = v3Global.debugFilename("order_edges.txt");
    const auto_ptr<ofstream> logp (V3File::new_ofstream(filename));
    if (logp->fail()) v3fatalSrc("Can't write "<<filename);

    deque<string> report;

    for (V3GraphVertex* itp = m_graph.verticesBeginp(); itp; itp=itp->verticesNextp()) {
	if (OrderVarVertex* vvertexp = dynamic_cast<OrderVarVertex*>(itp)) {
	    string name (vvertexp->varScp()->prettyName());
	    if (dynamic_cast<OrderVarPreVertex*>(itp)) name += " {PRE}";
	    else if (dynamic_cast<OrderVarPostVertex*>(itp)) name += " {POST}";
	    else if (dynamic_cast<OrderVarPordVertex*>(itp)) name += " {PORD}";
	    else if (dynamic_cast<OrderVarSettleVertex*>(itp)) name += " {STL}";
	    ostringstream os;
	    os.setf(ios::left);
	    os<<"  "<<setw(50)<<name<<" ";
	    AstSenTree* sentreep = vvertexp->domainp();
	    if (sentreep) {
		bool first = true;
		for (AstSenItem* itemp=sentreep->sensesp(); itemp; itemp=itemp->nextp()->castSenItem()) {
		    if (first) os<<"@( "; else os<<", ";
		    first = false;
		    os<<itemp->edgeType().verilogKwd();
		    if (itemp->varrefp()) {
			os<<" "+itemp->varrefp()->prettyName();
		    }
		}
		if (!first) os<<" )";
	    }
	    report.push_back(os.str());
	}
    }

    *logp<<"Signals and their clock domains:"<<endl;
    sort(report.begin(), report.end());
    for (deque<string>::iterator it=report.begin(); it!=report.end(); ++it) {
	*logp<<(*it)<<endl;
    }

}

//######################################################################
// Move graph construction

void OrderVisitor::processMoveClear() {
    OrderMoveDomScope::clear();
    m_pomWaiting.reset();
    m_pomReadyDomScope.reset();
    m_pomGraph.clear();
}

void OrderVisitor::processMoveBuildGraph() {
    // Build graph of only vertices
    UINFO(5,"  MoveBuildGraph\n");
    processMoveClear();
    m_pomGraph.userClearVertices();  // Vertex::user()   // OrderMoveVertex*, last edge added or NULL for none

    // For each logic node, make a graph node
    for (V3GraphVertex* itp = m_graph.verticesBeginp(); itp; itp=itp->verticesNextp()) {
	if (OrderLogicVertex* lvertexp = dynamic_cast<OrderLogicVertex*>(itp)) {
	    OrderMoveVertex* moveVxp = new OrderMoveVertex(&m_pomGraph, lvertexp);
	    moveVxp->m_pomWaitingE.pushBack(m_pomWaiting, moveVxp);
	    // Cross link so we can find it later
	    lvertexp->moveVxp(moveVxp);
	}
    }
    // Build edges between logic vertices
    for (V3GraphVertex* itp = m_graph.verticesBeginp(); itp; itp=itp->verticesNextp()) {
	if (OrderLogicVertex* lvertexp = dynamic_cast<OrderLogicVertex*>(itp)) {
	    OrderMoveVertex* moveVxp = lvertexp->moveVxp();
	    processMoveBuildGraphIterate(moveVxp, lvertexp, 0);
	}
    }
}

void OrderVisitor::processMoveBuildGraphIterate (OrderMoveVertex* moveVxp, V3GraphVertex* vertexp, int weightmin) {
    // Search forward from given logic vertex, making new edges based on moveVxp
    for (V3GraphEdge* edgep = vertexp->outBeginp(); edgep; edgep=edgep->outNextp()) {
	if (edgep->weight()!=0) { // was cut
	    int weight = weightmin;
	    if (weight==0 || weight>edgep->weight()) weight=edgep->weight();
	    if (OrderLogicVertex* toLVertexp = dynamic_cast<OrderLogicVertex*>(edgep->top())) {
		// Path from vertexp to a logic vertex; new edge
		// Note we use the last edge's weight, not some function of multiple edges
		new OrderEdge(&m_pomGraph, moveVxp, toLVertexp->moveVxp(), weight);
	    }
	    else { // Keep hunting forward for a logic node
		processMoveBuildGraphIterate(moveVxp, edgep->top(), weight);
	    }
	}
    }
}

//######################################################################
// Moving

void OrderVisitor::processMove() {
    // The graph routines have already sorted the vertexes and edges into best->worst order
    //   Make a new waiting graph with only OrderLogicVertex's
    //   (Order is preserved in the recreation so the sorting is preserved)
    //   Move any node with all inputs ready to a "ready" graph mapped by domain and then scope
    //	 While waiting graph ! empty  (and also known: something in ready graph)
    //     For all scopes in domain of top ready vertex
    //       For all vertexes in domain&scope of top ready vertex
    //	         Make ordered activation block for this module
    //	         Add that new activation to the list of calls to make.
    //	    	 Move logic to ordered active
    //		 Any children that have all inputs now ready move from waiting->ready graph
    //		 (This may add nodes the for loop directly above needs to detext)
    processMovePrepScopes();
    processMovePrepReady();

    // New domain... another loop
    UINFO(5,"  MoveIterate\n");
#ifdef NEW_ORDERING
    OrderMoveDomScope*  domScopep = NULL;	// Currently active domain/scope
    while (!m_pomReadyDomScope.empty()) {
	// Always need to reamin in same loop construct
	OrderLoopId curLoop = processMoveLoopCurrent();
	// Scan list to find search candidates
	OrderMoveDomScope*  loopHuntp = NULL;	// Found domscope under same loop
	OrderMoveDomScope*  domHuntp = NULL;	// Found domscope under same domain
	OrderMoveDomScope*  scopeHuntp = NULL;	// Found domscope under same scope
	if (domScopep) { UINFO(6,"           MoveSearch: loop="<<curLoop<<" "<<*domScopep<<endl); }
	else { UINFO(6,"           MoveSearch: loop="<<curLoop<<" NULL"<<endl); }
	for (OrderMoveDomScope* huntp = m_pomReadyDomScope.begin(); huntp; huntp = huntp->readyDomScopeNextp()) {
	    if (huntp->inLoop() == curLoop) {
		if (!loopHuntp) loopHuntp = huntp;
		if (domScopep && huntp->domainp() == domScopep->domainp()) {
		    if (!domHuntp) domHuntp = huntp;
		    if (domScopep && huntp->scopep() == domScopep->scopep()) {
			if (!scopeHuntp) scopeHuntp = huntp;
			break; // Exact match; all we can hope for
		    }
		}
	    }
	}
	// Recompute the next domScopep to process
	if (scopeHuntp) {
	    domScopep = scopeHuntp;
 	    UINFO(6,"     MoveIt: SameScope "<<*domScopep<<endl);
	} else if (domHuntp) { // No exact scope matches, try only matching the domain
	    domScopep = domHuntp;
 	    UINFO(6,"    MoveIt: SameDomain "<<*domScopep<<endl);
	} else if (loopHuntp) { // No exact scope or domain matches, only match the loop
	    domScopep = loopHuntp;
 	    UINFO(6,"   MoveIt: SameLoop "<<*domScopep<<endl);
	} else { // else we're hopefully all done
	    if (curLoop != LOOPID_NOTLOOPED)
		domScopep->domainp()->v3fatalSrc("Can't find more nodes like "<<*domScopep);  // Should be at least a "end loop"
	    break;
	}
	// Work on all vertices in this loop/domain/scope
	OrderMoveVertex* topVertexp = domScopep->readyVertices().begin();
	UASSERT(topVertexp, "domScope on ready list without any nodes ready under it");
	m_pomNewFuncp = NULL;
	while (OrderMoveVertex* vertexp = domScopep->readyVertices().begin()) {
	    processMoveOne(vertexp, domScopep, 1);
	    if (curLoop != processMoveLoopCurrent()) break;   // Hit a LoopBegin/end, change loop
	}
    }
    if (!m_pomWaiting.empty()) {
 	OrderMoveVertex* vertexp = m_pomWaiting.begin();
	vertexp->logicp()->nodep()->v3fatalSrc("Didn't converge; nodes waiting, none ready, perhaps some input activations lost: "<<vertexp<<endl);
    }
#else
    while (!m_pomReadyDomScope.empty()) {
 	// Start with top node on ready list's domain & scope
 	OrderMoveDomScope* domScopep = m_pomReadyDomScope.begin();
 	OrderMoveVertex* topVertexp = domScopep->readyVertices().begin();
 	UASSERT(topVertexp, "domScope on ready list without any nodes ready under it");
 	// Work on all scopes ready inside this domain
 	while (domScopep) {
 	    UINFO(6,"   MoveDomain l="<<domScopep->domainp()<<endl);
 	    // Process all nodes ready under same domain & scope
 	    m_pomNewFuncp = NULL;
 	    while (OrderMoveVertex* vertexp = domScopep->readyVertices().begin()) {
 		processMoveOne(vertexp, domScopep, 1);
 	    }
 	    // Done with scope/domain pair, pick new scope under same domain, or NULL if none left
 	    OrderMoveDomScope* domScopeNextp = NULL;
 	    for (OrderMoveDomScope* huntp = m_pomReadyDomScope.begin();
 		 huntp; huntp = huntp->readyDomScopeNextp()) {
 		if (huntp->domainp() == domScopep->domainp()) {
 		    domScopeNextp = huntp;
 		    break;
 		}
 	    }
 	    domScopep = domScopeNextp;
 	}
    }
    UASSERT (m_pomWaiting.empty(), "Didn't converge; nodes waiting, none ready, perhaps some input activations lost.");
#endif
    // Cleanup memory
    processMoveClear();
}

void OrderVisitor::processMovePrepScopes() {
    UINFO(5,"  MovePrepScopes\n");
    // Create a OrderMoveDomScope every domain/scope pairing
    for (OrderMoveVertex* vertexp = m_pomWaiting.begin(); vertexp; vertexp=vertexp->pomWaitingNextp()) {
	AstSenTree* domainp = vertexp->logicp()->domainp();
	AstScope* scopep = vertexp->logicp()->scopep();
	OrderLoopId inLoop = vertexp->logicp()->inLoop();
	// Create the dom pairing for later lookup
	OrderMoveDomScope* domScopep = OrderMoveDomScope::findCreate(inLoop, domainp, scopep);
	vertexp->domScopep(domScopep);
    }
}

void OrderVisitor::processMovePrepReady() {
    // Make list of ready nodes
    UINFO(5,"  MovePrepReady\n");
    for (OrderMoveVertex* vertexp = m_pomWaiting.begin(); vertexp; ) {
	OrderMoveVertex* nextp = vertexp->pomWaitingNextp();
	if (vertexp->isWait() && vertexp->inEmpty()) {
	    processMoveReadyOne(vertexp);
	}
	vertexp = nextp;
    }
}

void OrderVisitor::processMoveReadyOne(OrderMoveVertex* vertexp) {
    // Recursive!
    // Move one node from waiting to ready list
    vertexp->setReady();
    // Remove node from waiting list
    vertexp->m_pomWaitingE.unlink(m_pomWaiting, vertexp);
    // Add to ready list (indexed by domain and scope)
    vertexp->m_readyVerticesE.pushBack(vertexp->domScopep()->m_readyVertices, vertexp);
    vertexp->domScopep()->ready (this);
}

void OrderVisitor::processMoveDoneOne(OrderMoveVertex* vertexp) {
    // Move one node from ready to completion
    vertexp->setMoved();
    // Unlink from ready lists
    vertexp->m_readyVerticesE.unlink(vertexp->domScopep()->m_readyVertices, vertexp);
    vertexp->domScopep()->movedVertex (this, vertexp);
    // Don't need to add it to another list, as we're done with it
    // Mark our outputs as one closer to ready
    for (V3GraphEdge* edgep = vertexp->outBeginp(), *nextp; edgep; edgep=nextp) {
	nextp = edgep->outNextp();
	OrderMoveVertex* toVertexp = (OrderMoveVertex*)edgep->top();
	UINFO(9,"          Clear to "<<(toVertexp->inEmpty()?"[EMP] ":"      ")
	      <<toVertexp<<endl);
	// Delete this edge
	edgep->unlinkDelete(); edgep=NULL;
	if (toVertexp->inEmpty()) {
	    // If destination node now has all inputs resolved; recurse to move that vertex
	    // This is thus depth first (before width) which keeps the resulting executable's d-cache happy.
	    processMoveReadyOne(toVertexp);
	}
    }
}

void OrderVisitor::processMoveOne(OrderMoveVertex* vertexp, OrderMoveDomScope* domScopep, int level) {
    UASSERT(vertexp->domScopep() == domScopep, "Domain mismatch; list misbuilt?\n");
    OrderLogicVertex* lvertexp = vertexp->logicp();
    AstScope* scopep = lvertexp->scopep();
    UINFO(5,"    POSmove l"<<setw(3)<<level<<" d="<<(void*)(lvertexp->domainp())
	  <<" s="<<(void*)(scopep)<<" "<<lvertexp<<endl);
    AstSenTree* domainp = lvertexp->domainp();
    AstNode* nodep = lvertexp->nodep();
    AstModule* modp = scopep->userp()->castNode()->castModule();  UASSERT(modp,"NULL"); // Stashed by visitor func
    if (nodep->castUntilStable()) {
#ifdef NEW_ORDERING
	// Beginning of loop.
	if (OrderLoopBeginVertex* beginp = dynamic_cast<OrderLoopBeginVertex*>(lvertexp)) {
	    m_pomNewFuncp = NULL;  // Close out any old function
	    // Create new active record
	    string name = cfuncName(modp, domainp, scopep, nodep);
	    AstActive* callunderp = new AstActive(nodep->fileline(), name, domainp);
	    if (domainp == m_deleteDomainp) {
		UINFO(6,"      Delete loop "<<beginp<<endl);
		pushDeletep(callunderp);
	    } else {
		processMoveLoopStmt(callunderp);
	    }
	    // Put loop under the activate
	    nodep->unlinkFrBack();
	    callunderp->addStmtsp(nodep);
	    // Remember we're in a loop
	    processMoveLoopPush(beginp);
	}
	else if (OrderLoopEndVertex* endp = dynamic_cast<OrderLoopEndVertex*>(lvertexp)) {
	    // Nodep is identical to OrderLoopBeginVertex's, so we don't move it
	    m_pomNewFuncp = NULL;  // Close out any old function
	    processMoveLoopPop(endp->beginVertexp());
	}
	else {
	    nodep->v3fatalSrc("AstUntilStable node isn't under a OrderLoop{End}Vertex.\n");
	}
#else
	nodep->v3fatalSrc("Not implemented");
#endif
    }
    else if (nodep->castSenTree()) {
	// Just ignore sensitivities, we'll deal with them when we move statements that need them
    }
    else {  // Normal logic
	// Make or borrow a CFunc to contain the new statements
	if (v3Global.opt.profileCFuncs()
	    || (v3Global.opt.outputSplitCFuncs()
		&& v3Global.opt.outputSplitCFuncs() < m_pomNewStmts)) {
	    // Put every statement into a unique function to ease profiling or reduce function size
	    m_pomNewFuncp = NULL;
	}
	if (!m_pomNewFuncp && domainp != m_deleteDomainp) {
	    string name = cfuncName(modp, domainp, scopep, nodep);
	    m_pomNewFuncp = new AstCFunc(nodep->fileline(), name, scopep);
	    m_pomNewFuncp->argTypes(EmitCBaseVisitor::symClassVar());
	    m_pomNewFuncp->symProlog(true);
	    m_pomNewStmts = 0;
	    if (domainp->hasInitial() || domainp->hasSettle()) m_pomNewFuncp->slow(true);
	    scopep->addActivep(m_pomNewFuncp);
	    // Where will we be adding the call?
	    AstActive* callunderp = new AstActive(nodep->fileline(), name, domainp);
	    processMoveLoopStmt(callunderp);
	    // Add a top call to it
	    AstCCall* callp = new AstCCall(nodep->fileline(), m_pomNewFuncp);
	    callp->argTypes("vlSymsp");
	    callunderp->addStmtsp(callp);
	    UINFO(6,"      New "<<m_pomNewFuncp<<endl);
	}

	// Move the logic to the function we're creating
	nodep->unlinkFrBack();
	if (domainp == m_deleteDomainp) {
	    UINFO(4," Ordering deleting pre-settled "<<nodep<<endl);
	    pushDeletep(nodep); nodep=NULL;
	} else {
	    m_pomNewFuncp->addStmtsp(nodep);
	    if (v3Global.opt.outputSplitCFuncs()) {
		// Add in the number of nodes we're adding
		EmitCBaseCounterVisitor visitor(nodep);
		m_pomNewStmts += visitor.count();
	    }
	}
    }
    processMoveDoneOne (vertexp);
}

inline void OrderVisitor::processMoveLoopPush(OrderLoopBeginVertex* beginp) {
    UINFO(6,"      LoopPush  "<<beginp<<endl);
    m_pomLoopMoveps.push_back(beginp);
}

inline void OrderVisitor::processMoveLoopPop(OrderLoopBeginVertex* beginp) {
    UINFO(6,"      LoopPop   "<<beginp<<endl);
    if (m_pomLoopMoveps.empty()) beginp->nodep()->v3fatalSrc("processMoveLoopPop with no push'ed loops");
    OrderLoopBeginVertex* topBeginp = m_pomLoopMoveps.back();
    if (topBeginp != beginp) beginp->nodep()->v3fatalSrc("processMoveLoopPop had different vertex then one expected, got="<<topBeginp<<" exp="<<beginp<<endl);
    m_pomLoopMoveps.pop_back();
}

inline void OrderVisitor::processMoveLoopStmt(AstNode* newSubnodep) {
    if (m_pomLoopMoveps.empty()) {
	// Not in any loops, statements go into main body
	m_scopetopp->addActivep(newSubnodep);
    } else {
	// In a loop, put statements under appropriate loop body
	OrderLoopBeginVertex* topBeginp = m_pomLoopMoveps.back();
	topBeginp->untilp()->addBodysp(newSubnodep);
    }
}

inline OrderLoopId OrderVisitor::processMoveLoopCurrent() {
    // Return loopID we're currently processing
    if (m_pomLoopMoveps.empty()) {
	return LOOPID_NOTLOOPED;
    } else {
	OrderLoopBeginVertex* topBeginp = m_pomLoopMoveps.back();
	return topBeginp->loopId();  // Not inLoop, the begin is in the upper subloop.
    }
}

inline void OrderMoveDomScope::ready(OrderVisitor* ovp) {	// Check the domScope is on ready list, add if not
    if (!m_onReadyList) {
	m_onReadyList = true;
	UASSERT (inLoop()!=0, "Loop# 0 is illegal, perhaps should be LOOPID_NOTLOOPED?");
	m_readyDomScopeE.pushBack(ovp->m_pomReadyDomScope, this);
    }
}

inline void OrderMoveDomScope::movedVertex(OrderVisitor* ovp, OrderMoveVertex* vertexp) {	// Mark one vertex as finished, remove from ready list if done
    UASSERT(m_onReadyList, "Moving vertex from ready when nothing was on que as ready.");
    if (m_readyVertices.empty()) {	// Else more work to get to later
	m_onReadyList = false;
	m_readyDomScopeE.unlink(ovp->m_pomReadyDomScope, this);
    }
}

//######################################################################
// Top processing

void OrderVisitor::processLoops(string stepName, V3EdgeFuncP edgeFuncp) {
    UINFO(2,"    "<<stepName<<" Loop Detect...\n");
    m_graph.stronglyConnected(edgeFuncp);
    m_graph.dumpDotFilePrefixed((string)"orderg_"+stepName+"_strong", true);

    UINFO(2,"    "<<stepName<<" Insert Loop Begin/Ends...\n");
    processInsLoop();
    if (debug()>=4) m_graph.dumpDotFilePrefixed((string)"orderg_"+stepName+"_loops", true);

    // Remove loops from the graph
    UINFO(2,"    "<<stepName<<" Acyclic...\n");
    m_graph.acyclic(edgeFuncp);
    if (debug()) m_graph.dumpDotFilePrefixed((string)"orderg_"+stepName+"_acyc", true);

    // For any broken edges, add to change detect and remove edge
    UINFO(2,"    "<<stepName<<" ProcessBrokeLoop...\n");
    processBrokeLoop();
    if (debug()>=4) m_graph.dumpDotFilePrefixed((string)"orderg_"+stepName+"_broke", true);

    m_graph.makeEdgesNonCutable(edgeFuncp);
    m_graph.dumpDotFilePrefixed((string)"orderg_"+stepName+"_done", true);
}

void OrderVisitor::process() {
    // Dump data
    m_graph.dumpDotFilePrefixed("orderg_pre");

#ifdef NEW_ORDERING
    // Ignoring POST assignments and clocked statements, detect strongly connected components
    // Split components into subgraphs

    // Detect, loop begin/end, and acyc combo loops
    UINFO(2,"  Combo loop elimination...\n");
    processLoops("combo", &OrderEdge::followComboConnected);

    // Detect, loop begin/end, and acyc post assigns
    UINFO(2,"  Sequential loop elimination...\n");
    processLoops("sequent", &OrderEdge::followSequentConnected);

    // Detect and acyc any PRE assigns
    // As breaking these does not cause any problems, we don't need to loop begin/end, etc.
    UINFO(2,"  Pre Loop Detect & Acyc...\n");
    m_graph.stronglyConnected(&V3GraphEdge::followAlwaysTrue);
    if (debug()>=4) m_graph.dumpDotFilePrefixed("orderg_preasn_strong", true);
    m_graph.acyclic(&V3GraphEdge::followAlwaysTrue);
    m_graph.dumpDotFilePrefixed("orderg_preasn_done", true);
#else
    // Break cycles
    UINFO(2,"  Acyclic & Order...\n");
    m_graph.acyclic(&V3GraphEdge::followAlwaysTrue);
    m_graph.dumpDotFilePrefixed("orderg_acyc");
#endif

    // Assign ranks so we know what to follow
    // Then, sort vertices and edges by that ordering
    m_graph.order();
    m_graph.dumpDotFilePrefixed("orderg_order");

#ifndef NEW_ORDERING
    UINFO(2,"  Process Circulars...\n");
    processCircular();  // must be before processDomains
#endif

    // Assign logic verticesto new domains
    UINFO(2,"  Domains...\n");
    processDomains();
    m_graph.dumpDotFilePrefixed("orderg_domain");

    if (debug() && v3Global.opt.dumpTree()) processEdgeReport();

    UINFO(2,"  Construct Move Graph...\n");
    processMoveBuildGraph();
    if (debug()>=4) m_pomGraph.dumpDotFilePrefixed("ordermv_start");  // Different prefix (ordermv) as it's not the same graph
    m_pomGraph.removeRedundantEdges(&V3GraphEdge::followAlwaysTrue);
    m_pomGraph.dumpDotFilePrefixed("ordermv_simpl");

    UINFO(2,"  Move...\n");
    processMove();

    // Any SC inputs feeding a combo domain must be marked, so we can make them sc_sensitive
    UINFO(2,"  Sensitive...\n");
    processSensitive();  // must be after processDomains

    // Dump data
    m_graph.dumpDotFilePrefixed("orderg_done");
    if (0 && debug()) {
	string dfilename = v3Global.opt.makeDir()+"/"+v3Global.opt.prefix()+"_INT_order.tree";
	const auto_ptr<ofstream> logp (V3File::new_ofstream(dfilename));
	if (logp->fail()) v3fatalSrc("Can't write "<<dfilename);
	m_graph.dump(*logp);
    }
}

//######################################################################
// Order class functions

void V3Order::orderAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    OrderVisitor visitor;
    visitor.main(nodep);
}